I will resend this to fix the subject line - steve On 7/14/2025 3:07 PM, Steve Sistare wrote:
Regions for sub-page BARs are normally mapped here, in response to the guest writing to PCI config space:vfio_pci_write_config() pci_default_write_config() pci_update_mappings() memory_region_add_subregion() vfio_sub_page_bar_update_mapping() ... vfio_dma_map() However, after CPR, the guest does not reconfigure the device and the code path above is not taken. To fix, in vfio_cpr_pci_post_load, call vfio_sub_page_bar_update_mapping for each sub-page BAR with a valid address. Fixes: 7e9f21411302 ("vfio/container: restore DMA vaddr") Signed-off-by: Steve Sistare <steven.sist...@oracle.com> --- hw/vfio/pci.h | 1 + hw/vfio/cpr.c | 2 ++ hw/vfio/pci.c | 14 ++++++++++++++ 3 files changed, 17 insertions(+) diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h index 495fae7..cb1310d 100644 --- a/hw/vfio/pci.h +++ b/hw/vfio/pci.h @@ -228,6 +228,7 @@ void vfio_pci_write_config(PCIDevice *pdev, uint64_t vfio_vga_read(void *opaque, hwaddr addr, unsigned size); void vfio_vga_write(void *opaque, hwaddr addr, uint64_t data, unsigned size);+void vfio_sub_page_bar_update_mappings(VFIOPCIDevice *vdev);bool vfio_opt_rom_in_denylist(VFIOPCIDevice *vdev); bool vfio_config_quirk_setup(VFIOPCIDevice *vdev, Error **errp); void vfio_vga_quirk_setup(VFIOPCIDevice *vdev); diff --git a/hw/vfio/cpr.c b/hw/vfio/cpr.c index af0f12a..384b56c 100644 --- a/hw/vfio/cpr.c +++ b/hw/vfio/cpr.c @@ -116,6 +116,8 @@ static int vfio_cpr_pci_post_load(void *opaque, int version_id) PCIDevice *pdev = &vdev->pdev; int nr_vectors;+ vfio_sub_page_bar_update_mappings(vdev);+ if (msix_enabled(pdev)) { vfio_pci_msix_set_notifiers(vdev); nr_vectors = vdev->msix->entries; diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 1093b28..9c616bd 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2826,6 +2826,20 @@ static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f) return ret; }+void vfio_sub_page_bar_update_mappings(VFIOPCIDevice *vdev)+{ + PCIDevice *pdev = &vdev->pdev; + int page_size = qemu_real_host_page_size(); + int bar; + + for (bar = 0; bar < PCI_ROM_SLOT; bar++) { + PCIIORegion *r = &pdev->io_regions[bar]; + if (r->addr != PCI_BAR_UNMAPPED && r->size > 0 && r->size < page_size) { + vfio_sub_page_bar_update_mapping(pdev, bar); + } + } +} + static VFIODeviceOps vfio_pci_ops = { .vfio_compute_needs_reset = vfio_pci_compute_needs_reset, .vfio_hot_reset_multi = vfio_pci_hot_reset_multi,
